Patient-specific acetabular guide for anterior approach

ABSTRACT

An orthopedic device includes a patient-specific acetabular guide that can be used for preparing an acetabulum of a patient to receive an acetabular implant. The acetabular guide has a body with an outer three-dimensional surface configured to match an acetabulum of a specific patient&#39;s hip joint designed from data of the patient&#39;s hip joint. The acetabular guide can further include a peripheral annular rim.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/790,770, filed on Mar. 8, 2013, which is a continuation-in-part ofU.S. patent application Ser. No. 13/711,306, filed on Dec. 11, 2012, nowissued as U.S. Pat. No. 9,060,788, entitled Patient-Specific AcetabularGuide for Anterior Approach. The entire disclosure of the aboveapplications are incorporated herein by reference.

FIELD

The present teachings relate to an acetabular guide and particularly toa patient-specific guide and various associated instruments.

INTRODUCTION

The present teachings provide a patient-specific acetabular guide andassociated instruments for implanting an acetabular implant into anacetabulum of a patient for hip joint arthroplasty.

SUMMARY

The present teachings provide various instruments and methods forgenerally preparing the acetabulum of a patient to receive an acetabularimplant, such as, for example, an acetabular cup along an alignmentaxis. The alignment axis and various patient-specific guides and otherassociated instruments can be designed during a pre-operative plan usinga three-dimensional reconstruction of the patient's relevant anatomy,such as the pelvis or portions thereof, including the acetabular andperiacetabular areas of the pelvis. The three-dimensional reconstructioncan be based on medical images, including MRI, CT, ultrasound, or X-rayscans and prepared using commercially available imaging software.

The present teachings provide, for example, a patient-specificacetabular guide that can be used for preparing an acetabulum of apatient to receive an acetabular implant, such as an acetabular cup. Theacetabular guide has a dome-shaped body with a peripheral annular rimand an outer three-dimensional surface configured to match an acetabulumof a specific patient's hip joint from three-dimensional medical imagesof the patient's hip joint during a preoperative plan for the patient. Apatient-specific registration guide can be permanently or removablyattached to the peripheral rim. The patient-specific registration guidehas a longitudinal bore defining a patient-specific alignment axis withan alignment orientation configured for guiding an acetabular implantfor the patient during the preoperative plan of the patient. Theregistration guide has a patient-specific undersurface configured tomate with a corresponding portion of a periacetabular surface and/oracetabular rim surface of the acetabulum of the patient.

In some embodiments, the acetabular guide can include a plurality ofspaced-apart registration hooks. Each registration hook can extend fromand be attached to the peripheral rim of the acetabular guide. Eachregistration hook has a patient-specific undersurface configured to matewith a corresponding surface of the acetabular rim of the patient'sacetabulum.

The present teachings also provide a method for hip joint arthroplasty.The method includes inserting a patient-specific acetabular guide intoan acetabulum of a patient. A patient specific undersurface of adome-shaped body of the acetabular guide mates substantially as negativeof a corresponding surface of the acetabulum. At least onepatient-specific registration hook extends from a peripheral rim of theacetabular guide over a portion of an acetabular rim of the acetabulum.The method includes inserting an alignment pin into the patient's bonethrough a bore of a patient-specific registration guide. Thepatient-specific registration guide is removably attached to theperipheral rim of the acetabular guide. The patient-specificregistration guide is preoperatively configured to define apatient-specific alignment orientation for inserting an acetabularimplant. The method includes removing the acetabular guide withoutremoving the alignment pin and inserting an acetabular implant along anorientation parallel to the alignment pin.

In some embodiments, the acetabular guide can be inserted into theacetabulum using an inserter with a removable adapter element. A distalbore of the adapter element can be coupled to a first post of theacetabular guide. A second post of the acetabular guide can held betweenfirst and second flanges extending from the adapter element.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1A is a front isometric view of a patient-specific acetabular guideaccording to the present teachings;

FIG. 1B is a back isometric view patient-specific acetabular guide ofFIG. 1A

FIG. 2A is an isometric environmental view of the patient-specificacetabular guide of FIG. 1;

FIG. 2B is another isometric environmental view of the patient-specificacetabular guide of FIG. 1 shown the axial plane, the sagittal andanterior pelvic plane;

FIG. 3 is an isometric environmental view of the patient-specificacetabular guide of FIG. 1 shown with a tip element of an acetabularguide inserter according to the present teachings;

FIG. 4 is an isometric view of the patient-specific acetabular guide ofFIG. 1 shown with the tip element of FIG. 3;

FIG. 5 is an isometric environmental view of an acetabular implant;

FIG. 6 is a bottom view of the instrument handle tip element shown inFIG. 4;

FIG. 7 is a top view of the instrument handle tip element shown in FIG.4;

FIG. 8 is an isometric view of an acetabular guide inserter shown withthe tip element of FIG. 6;

FIG. 9 is an isometric view of the acetabular guide inserter of FIG. 7shown without the tip element;

FIG. 10 is an isometric view of the inserter of FIG. 7 coupled to thepatient-specific acetabular guide of FIG. 1 according to the presentteachings;

FIG. 11 is an environment isometric view of the inserter of FIG. 7coupled to the patient-specific acetabular guide of FIG. 1 according tothe present teachings;

FIGS. 12A and 12B illustrate top isometric views of a patient-specificacetabular guide according to the present teachings;

FIG. 13 illustrates a detail isometric environmental view of thepatient-specific acetabular guide of FIG. 12A; and

FIG. 14 illustrates a lesser detail isometric environmental view of thepatient-specific acetabular guide of FIG. 12A.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses.

The present teachings generally provide patient-specific acetabularalignment guides, inserters and/or other associated instruments for usein orthopedic surgery, such as, for example, in joint replacement orrevision surgery for the hip. The patient-specific alignment guides andassociated instruments can be used either with conventional or withpatient-specific implant components prepared with computer-assistedimaging methods based on medical scan of the specific patient.

As described in commonly assigned U.S. Pat. No. 8,092,465, issued Jan.1, 2012, and co-pending U.S. patent application Ser. No. 13/400,652,filed Feb. 21, 2012, both of which are incorporated by reference herein,during a preoperative planning stage, imaging data of the relevantanatomy of a patient can be obtained at a medical facility or doctor'soffice. The imaging data can include, for example, a detailed scan of apelvis, hip, knee, ankle or other joint or relevant portion of thepatient's anatomy. The imaging data can be obtained using an MRI, CT,and X-Ray, ultrasound or any other imaging systems. The imaging dataobtained can be used to construct a three-dimensional computer image ofthe joint or other portion of the anatomy of the patient and prepare aninitial preoperative plan that can include bone or joint preparation,such as planning for resections, milling, reaming, broaching, as well asimplant selection and fitting, design of patient-specific guides,templates, tools and alignment protocols for the surgical procedure.Additionally, physical modes of the patient's joint and associated bonescan be prepared for visualization and trialing of the guides andimplants prior to the surgical procedure.

Computer modeling for obtaining three-dimensional computer images of therelevant patient's anatomy can be provided by various CAD programs,applications and/or software commercially available from various vendorsor developers, such as, for example, from by Object Research Systems orORS, Montreal, Canada. The computer modeling program or otherapplication can be configured and used to plan a preoperative surgicalplan, including planning various bone preparation procedures, to selector design/modify implants and design patient-specific guides and toolsincluding patient-specific prosthesis components, and patient-specifictools, including reaming, broaching, milling, drilling or cutting tools,alignment guides, templates and other patient-specific instruments.

The preoperative plan can be stored in any computer storage medium, in acomputer file form or any other computer or digital representation,including three-dimensional graphical files or digital data sets. Thepreoperative plan, in a digital form associated with interactivesoftware or other application, can be made available via a hard medium,a web-based or mobile or cloud service, or a cellular portable device tothe surgeon or other medical practitioner, for review. Using theinteractive software or application, the surgeon can review the plan,and manipulate the position of images of various implant componentsrelative to an image of the anatomy. The surgeon can modify the plan andsend it to the manufacturer with recommendations or changes. Theinteractive review process can be repeated until a final, approved plan,is sent to a manufacturing facility for preparing the actual physicalcomponents. In other embodiments, physical and digital patient-specificbone models guides and instruments and can be provided preoperatively tothe surgeon for trialing and marking.

After the surgical plan is approved by the surgeon, patient-specificimplants and associated tools, including, for example, alignment guides,cutting/milling/reaming/broaching or other tools for the surgicalpreparation of the joint or other anatomy portion of the specificpatient can be designed using a CAD program or other three-dimensionalmodeling software, such as the software provided by Object ResearchSystems or ORS, Montreal, Canada, for example, according to thepreoperative surgical plan. Patient-specific guides and otherinstruments can be manufactured by various stereolithography methods,selective laser sintering, fused deposition modeling or other rapidprototyping methods. In some embodiments, computer instructions of toolpaths for machining the patient-specific guides and/or implants can begenerated and stored in a tool path data file. The tool path data can beprovided as input to a CNC mill or other automated machining system, andthe tools and implants can be machined from polymer, ceramic, metal orother suitable material depending on the use, and sterilized. Thesterilized tools and implants can be shipped to the surgeon or medicalfacility for use during the surgical procedure.

Patient-specific implants, guides, templates, tools or portions thereofare defined herein as those constructed by a preoperative plan for aspecific patient from three-dimensional images of the specific patient'sanatomy reconstructed from preoperative medical scans of the patient.The patient-specific components are constructed to closely conform andmate or match substantially as a negative mold or negative surface orinverse or mirror surface of corresponding surface portions of thepatient's anatomy, including bone surfaces with or without associatedsoft tissue, such as articular cartilage, for example, depending on theparticular procedure, implant and tool use. Minute irregularities of thepatient's joint surfaces need not be mirrored.

As discussed above, patient-specific alignment guides and implants aregenerally configured to match the anatomy of a specific patient and canfit in only one position on a corresponding surface of the specificpatient because anatomic features that are unique to each patient canfunction as landmarks and can guide placement of the alignment guide orimplant in only one position without the need of intraoperativenavigation, patient marking or other intraoperative guidance. Thepatient-specific alignment guides are generally configured andmanufactured using computer modeling based on the patient's 3-D anatomicimage and have an engagement surface that is made to conforminglycontact and match as a mirror or negative or inverse surface to acorresponding surface of a three-dimensional image/model of thepatient's bone surface (with or without cartilage or other soft tissue),by the computer methods discussed above. Generally, the patient specificguide has an exterior surface that contacts about 80% of the patient'sanatomy when properly positioned, including about 90%, and about 98%.The exterior surface of the patient matched guide can, therefore,substantially mate with the selected portion of the anatomy. It isunderstood, however, that certain exterior portions of a patientspecific guide may not have substantial contact with the patient, whileother portions are designed to ensure contact even when other portionsare not contacting the patient. Thus, a patient matched guide can haveportions that are substantially patient matched and have or can achievethe selected amount of contact with the patient.

The patient-specific alignment guides can include one or morecustom-made guiding formations, such as, for example, guiding bores orcannulated guiding posts or cannulated guiding extensions or receptaclesthat can be used for supporting or guiding other instruments, such asdrill guides, reamers, cutters, cutting guides and cutting blocks or forinserting pins or other fasteners according to a surgeon-approvedpre-operative plan. The patient-specific alignment guides can be used inminimally invasive surgery, and also in surgery with multipleminimally-invasive incisions. Various alignment guides and pre-operativeplanning procedures are disclosed in commonly assigned U.S. Pat. No.8,092,465, issued Jan. 10, 2012; U.S. Pat. No. 8,070,752, issued Dec. 6,2011; U.S. Pat. No. 8,133,234, issued Mar. 13, 2012; co-pending U.S.patent application Ser. No. 12/211407, filed Sep. 16, 2008; co-pendingU.S. patent application Ser. No. 12/025414, filed Feb. 4, 2008;co-pending 13/111007, filed May 19, 2011; co-pending U.S. patentapplication Ser. No. 13/041469, filed Mar. 7, 2011; and co-pending U.S.patent application Ser. No. 13/400652, filed Feb. 21, 2012. Thedisclosures of the above patents and applications are incorporatedherein by reference.

Referring to FIGS. 1A-9, the present teachings provide apatient-specific acetabular guide 100 and an acetabular guide inserter300 an adapter element 350. As discussed herein, the adapter element mayor may not be removable from a handle portion during operation. Theacetabular guide 100 can be used in connection with various otherinstruments to generally provide a patient-specific alignment axis A.The patient-specific alignment axis A is used to insert an alignment pin230 and generally to orient, insert, and implant an acetabular implantor acetabular cup 250 in an acetabulum (or acetabulum cavity) 82 of thepatient, to facilitate guided reaming of the acetabulum 82, andgenerally guide any instruments and procedures relative to the alignmentaxis A or the alignment pin 230. The alignment axis A is determinedduring the preoperative plan from the three-dimensional image of the hipjoint of the patient as the axis along which the acetabular implant 250is to be centered and inserted. The alignment axis A is generallyperpendicular the acetabulum 82 and corresponding acetabular engagementsurface 252 of the acetabular implant 250. More specifically, withreference to FIG. 2B, the orientation (i.e., angles) of the alignmentaxis A can be selected and specified relative the axial plane (AP),sagittal plane (SP) and anterior pelvic plane (APP). The coronal planeis a vertical plane that is orthogonal to the axial and sagittal planes(not shown). The anterior pelvic plane (APP) is defined as a planepassing through the two anterior iliac spines and the pubic symphysis ofthe pelvis 80 of the patient. The APP may deviate from being parallel tothe coronal plane when viewed in the weight-bearing profile of thepatient (standing). Additionally, the APP plane may have a differentorientation in the supine position. The deviation varies from patient topatient, such that the anterior pelvic plane cannot be relied on by thesurgeon without additional information to guide the acetabular implantand avoid impingement during motion. The angle between the anteriorpelvic plane and the coronal plane can be referenced as a pelvic tiltand is zero when the anterior pelvic plane is parallel to the coronalplane. The present teachings determine a patient-specific axis forinserting an acetabular implant. The patient-specific alignment axis isphysically and uniquely identified by the orientation of an alignmentpin inserted into the bone using the patient-specific acetabular guideand landmark registration incorporated into the acetabular guide duringthe preoperative plan. Specifically, the preoperative plan that is basedon images of the hip joint of the patient can accurately determine theorientation of the alignment axis A and fix it intraoperatively via thepatient-specific acetabular guide 100 on the pelvis 80 of the patient toguide the surgeon during the surgical procedure.

The patient-specific acetabular guide 100 can engage the acetabulum 82of the specific patient in a unique (only one) position and can providean accurate alignment axis A relative to the planned orientation of theacetabular implant 250. The patient-specific acetabular guide 100 canalso provide secure fitting and rotational stability in a design that islightweight and has compact size and small bulk.

FIGS. 1A-3 illustrate a patient-specific acetabular guide 100 that has adome-shaped body 102 with a three dimensional patient-specificundersurface or outer surface 104 configured to contact and engage theacetabulum 82. The outer surface 104 is designed and/or formed to matchas a negative of a corresponding surface of the acetabulum 82 from thethree-dimensional image of the patient's hip joint. Thus, the outersurface 104 is formed to mate closely, such as to contact about 85% toabout 100% of the acetabulum 82 when positioned in the acetabulum 82.

The dome-shaped body 102 of the patient-specific acetabular guide 100can have one or more openings in the form of windows 106 that reduce theweight of the patient-specific acetabular guide 100 and provide improvedvisualization of the underlying anatomy. The dome-shaped body 102 canalso include additional holes or other apertures 109 for drilling holesin the acetabulum 82 and corresponding to holes 254 for fixation screwsof the acetabular implant 250. The dome-shaped body 102 of thepatient-specific acetabular guide 100 is bounded by a guide rim 108 inthe form of a closed-contour peripheral annular surface that has anuneven, irregular, jagged or wavy shape that follows the correspondingirregular shape of an acetabular rim 84 (and periacetabular surface)around the acetabulum 82 of the patient. Additionally, thepatient-specific acetabular guide 100 can include one or moreregistration hooks or extensions 110 that extend from the guide rim 108along a three-dimensional curved surface around the acetabular rim 84 atdifferent and spaced-apart positions. The registration hooks 110 areconfigured to provide additional registration locations for thepatient-specific acetabular guide 100 by replicating correspondingunderlying surface portions or landmarks of the acetabular rim 84 in apatient-specific manner. Specifically, each registration hook 110 canhave a curved (three-dimensional) undersurface 112 that ispatient-specific and negative of the surface of the acetabular rim 84 atspecific locations selected as landmark locations during thepreoperative plan for the patient. Each registration hook 110 caninclude a hole 114 for receiving a fixation pin or other fixationelement 116 (shown in FIG. 4) for attaching the patient-specificacetabular guide 100 to the pelvis of the patient.

The patient-specific acetabular guide 100 can include a removable ornon-removable registration and alignment guide 120 (referenced asregistration guide 120, for short) that has a longitudinal bore 124along the patient-specific alignment orientation A. A removable drillinsert 122 with a longitudinal bore 126 can be received concentricallyin the bore 124 of the registration guide 120. The wall of the bore 124of the registration guide 120 can define a taper that engages acomplementary taper 127 of an end of the removable drill insert 122. Thecomplementary tapers can ensure appropriate and selected alignment ofthe bore 124 and the insert bore 126. Thus, the bore 124 and the insertbore 126 can be concentric and coextensive.

The drill insert 122 can provide stability during the insertion of analignment pin 230 that can define the alignment axis A. The alignmentpin 230 can include a drill tip 231 that can drill into the bone of ornear the acetabulum. The alignment pin 230 is received into theconcentric and coextensive bores 124, 126 of the registration guide 120and of the drill insert 122. Accordingly, the alignment pin 230 isoriented along the alignment axis A. The drill insert 122 can be formedof a tough and/or strong material. For example, the drill insert 122 canbe metallic and reusable, while the registration guide 120 and theacetabular guide 100 are patient-specific and can be made of a softermaterial, such as a polymer material, and can be disposable. The toughmaterial of the drill insert 122 can engage the alignment pin 230without deformation and protect the registration guide 120 from damagedue to engaging the alignment pin 230.

The registration guide 120 has an undersurface portion that is apatient-specific undersurface 128 that can hook around or snap-on orotherwise engage and contact the guide rim 108 at a pre-defined markedlocation determined during the preoperative plan of the patient. Theregistration guide 120 that includes the patient-specific undersurface128 matches the surface of the acetabular rim 84 and/or periacetabulararea of the pelvis 80 of the patient at a corresponding location. Thebore 124 of the registration guide 120 and the bore 126 of the drillinsert 122 can have an open (i.e., non-continuous) periphery defining alongitudinal slit 133 that is configured to allow the patient-specificacetabular guide 100 to be removed from the pelvis of the patientwithout removing the alignment pin 230 that is inserted into the pelvis80 and defines the alignment axis A. In other words, thepatient-specific acetabular guide 100 can be also removed by side orlateral motion relative to the slit 133 and the longitudinal axis A andnot necessarily by only motion along the alignment axis A or along thealignment pin 230.

The patient-specific acetabular guide 100 can include first and secondposts 130, 132 extending from an interior surface 105 (opposite to outersurface 104) of the dome-shaped body 102 of the patient-specificacetabular guide 100. The first post 130 can be tubular and can define abore 134 that passes through the dome-shaped body 102 of the acetabularguide for optional fixation to the acetabulum 82 using a pin or otherfastener. The bore 134 is not necessary, however, and the post 130 canbe a closed hollow post or a solid post. The first post 130 can becentrally located and perpendicular relative to the dome-shaped body 102of the patient-specific acetabular guide 100 and the underlying surfaceof the acetabulum 82. The second post 132 can be offset relative to thefirst post 130 along a radial direction relative to the periphery of theguide rim 108. The second post 132 can be shorter in height relative tothe first post 130. The posts 130, 132 can be used to insert thepatient-specific acetabular guide 100 using an acetabular guideinserter, such as the acetabular guide inserter 300 shown in FIG. 8.

It should be noted that other inserters can also be used to connect toone or both posts 130, 132 and be coupled to the patient-specificacetabular guide 100. According to various embodiments, the acetabularguide inserter 300 can be modular and include an elongated portion 302and the adapter element (or inserter tip) 350 can be removable from theelongated portion 302. The elongated portion 302 can include a handleportion 308 and a shaft 304 having a distal post or boss 306. Theadapter element 350 includes a tubular post 352 with a first bore 354configured to connect and receive the boss 306 of the elongated portion302 of the acetabular guide inserter 300. The elongated portion 302 canbe interconnected to the adapter 350 at an appropriate time to insertthe guide 100 (e.g. after the adapter 350 has engaged the post 130). Itis understood, however, that the adapter can be manufactured to be fixedto the elongated portion 302 for use. For example, the elongated portion302 and the adapter 350 can be formed as one piece or fixed together,such as with welding or an adhesive. Accordingly, it is understood thatthe inserter 300 need not be separable for use by a user.

The adapter element 350 includes a second bore 355 opposite to the firstbore 354 and configured to receive the first tubular post 130 of theacetabular guide 100. The adapter element 350 includes first and secondarms or flanges 356, 358 extending from a distal end of the adapterelement 350 opposite to the post 352 and around the second bore 355. Thefirst and second flanges 356, 358 define an open channel or a U-shapedinner surface 360 that can receive and hold the second post 132. Thefirst and second flanges 356, 358 can be resiliently coupled to adapterelement 350 and can be configured to snap-on to the second post 132 ofthe patient-specific acetabular guide 100 while the first post 130 ofthe acetabular guide 100 is received in the second bore 355 of theadapter element 350, as shown in FIGS. 3, 4 and 10.

The patient-specific acetabular guide 100 can be inserted in theacetabulum 82 using the inserter 300, as shown in FIG. 9. The inserter300 can be removed, and the patient-specific acetabular guide 100 can bestabilized to the bone with fixation pins 232. A hole can be drilledthrough the drill insert 122 into the bone and the alignment pin 230 canbe inserted along the alignment axis A defined by the registration guide120. It is understood, that inserting the alignment pin 230 need not bea two-step process. For example, the alignment pin 230 can include adrill tip or portion 231 such that the alignment pin 230 is directlydrilled into the bone.

Other holes can also be drilled into the bone through the holes 109 ofthe patient-specific acetabular guide 100 for attaching the acetabularimplant 250. The fixation pins 232 can be removed and then thepatient-specific acetabular guide 100 can be removed sideways withoutremoving the alignment pin 230 and without disturbing its orientationalong the alignment axis A. The acetabular implant 250 can be insertedin the acetabulum along an axis A′ parallel to the alignment axis Adefined by the alignment pin 230 that is still attached to the bone.Additionally, reaming or other acetabular bone preparations can beperformed using the orientation defined by the alignment pin 230 priorto the insertion of the acetabular implant 250.

The patient-specific acetabular guide 100 does not require the use ofadditional secondary guides to provide an alignment orientation forinserting an acetabular implant 250 or guiding other instruments. Assuch, the patient-specific acetabular guide 100 can be conveniently usedin hip arthroplasty with an anterior supine incision along apatient-specific alignment axis A. The alignment axis A ispreoperatively determined and transferred to the pelvis 80 using analignment pin 230 guided by the registration guide 120 of thepatient-specific acetabular guide 100, as discussed above.

According to various embodiments, an acetabular guide 500 is illustratedin FIGS. 12A-14. The acetabular guide 500 can be similar to theacetabular guide 100, discussed above, including variations discussedfurther herein. Nevertheless, the acetabular guide 500 can be insertedor positioned in the acetabulum 82 of the pelvis 80, in a manner similarto that of the acetabular guide 100.

The acetabular guide 500 can be positioned to allow for guidingplacement of the alignment pin 230 at a selected location in the pelvis80, as discussed further herein. The alignment pin 230 can be positionedto illustrate or identify a predetermined alignment axis A, as discussedabove. The alignment pin 230 can be positioned through the removabledrill insert 122 that is positioned in a removable or non-removableregistration or alignment guide 520. The acetabular guide 500 caninclude portions that are substantially similar to portions of thealignment guide 100, and will not be described in detail here. Theacetabular guide 500 can include an outer dome surface 504 that can bepositioned to engage the acetabulum 82 in a manner similar to the outerdome surface 104 of the acetabular guide 100, as discussed above.Accordingly, the outer dome surface 504 and/or an upper rim 508 caninclude a geometrical configuration that are substantially similar ormirror the acetabulum or the rim of the acetabulum 82. For example, themirror surface or patient matched surface can contact any selectedamount of the acetabulum, such as greater than about 80%, includingabout 80%-90%, including further at least about 98%. Accordingly, theacetabular guide 520 can be substantially patient matched. Thedetermination or geometry of the acetabular guide 500 can be based onvarious techniques, including image data obtained of the patient in aprocess as discussed above. The dome surface 504 and other portions ofthe guide 500 can be designed to be patient matched for engaging thepatient in substantially only one orientation and location.

The acetabular guide 500 can further include various portions thatengage an upper rim or edge or a portion external to the acetabulum 82.For example, the acetabular guide 500 can include one or moreregistration hooks 510. The registration hooks 510 can include ageometry or structure that extends from the upper rim 508, in one ormore dimensions, to have an external engaging or contacting fingerportion 511. The geometry of the registration hook 510 can furtherinclude a reinforcing rib portion 512 that extends at least a portion ofa length of the registration hook 510 to assist in providing rigidityand/or geometrical stability to the registration hooks 510.

The registration hooks 510 can be positioned at various positions aroundthe rim 508 of the registration guide 500. However, it is understood,that various registration hooks are not required and may be selected tobe removed or not provided with the acetabular guide 500. For example, aregistration hook that is positioned or would be positioned near anischium of the pelvis 80, such as an ischial registration hook 510 c,need not be required. According to various embodiments, therefore, forexample, for efficiency of manufacturing, the ischial registration hook510 c may not be provided. Nevertheless, the registration hooks 510 aand 510 b can be provided to assist in providing additional registrationlocations relative to the acetabular guide 500. Generally, the dome 504of the acetabular guide 500 can provide appropriate registration of theacetabular guide 500 relative to the acetabulum 82 of the patient. Asdiscussed herein, the registration of the hooks 510 and/or the dome 504can ensure that the guide 500 is located and oriented at a pre-selectedlocation and orientation relative to the pelvis 80 of the specificpatient.

The acetabular guide 500 can also be positioned and held in placerelative to the patient and the acetabulum 82 based upon the geometry ofthe dome 504 and/or the registration hooks 510 a and/or 510 b.Accordingly, additional fixation mechanisms, such as pins positionedthrough holes in the registration hooks 510 need not be provided. It isunderstood, however, that additional fixation mechanisms, such as pinspositioned through the registration hooks 510, can be provided. Also,additional fixation holes 509 can be formed through the dome 504 toreceive fixation pins or screws into the acetabulum 82.

Additionally, the alignment or registration guide 520 can be formed andpositioned to be integral or connected to at least one of theregistration hooks 510 b. The positioning of the alignment guide 520relative to the registration hook 510 b is not required, but thecombination can assist in providing rigidity and strength to each of thealignment guide 520 and the registration hook 510 b. Additionally, theposition of the registration hook 510 b can be aligned with orpositioned relative to the alignment guide 520 due to a positioning orselected positioning of the alignment pin 230 relative to the acetabulum82. As discussed herein, the pin 230 is positioned through an alignmentbore 524 formed through the alignment guide 520.

The acetabular guide 500 can be positioned within the acetabulum 82 in amanner substantially similar to the acetabular guide 100, discussedabove, as exemplarily illustrated in FIGS. 13 and 14. The acetabularguide 500 can be positioned with the inserter 300, as discussed above.The inserter can engage a first post 530, such as with a central bore orblind bore formed in the inserter 300. The inserter 300 can furtherinclude one or more fingers or flanges 356 and 358, as discussed above,to engage a second or additional post 532. The acetabular guide 500,therefore, can be positioned within the acetabulum 82 of the patientsubstantially as discussed above, and as illustrated in FIGS. 3 and 4.The posts 530 and 532, however, can be closed and need not include anypassages or fixation portions to assist in holding the acetabular guide500 relative to the acetabulum 82. It is understood that other passages,such as the passage 509, can be formed through the guide 500 to allowfor positioning of various fixation portions through the acetabularguide 500.

Additionally, viewing passages 506 can be formed through the guide 500to assist in viewing the acetabulum 82 of the patient. The viewingpassages 506 can allow a user to view the acetabulum 82 during and afterplacement of the guide 500. This can assist in ensuring that theacetabular guide 500 is positioned within the patient in the acetabulum82 in a selected manner.

The acetabular guide 500 is positioned within the acetabulum 82 suchthat the alignment guide 520 is selectively positioned relative to theinferior ischial spine. In particular, when the drill guide 122 ispositioned within the alignment bore 524, then the alignment pin 230that is passed through the drill guide 122 is on a line 580 that extendsthrough the central post 530 and the interior spine of the ischium 570,as illustrated in FIG. 14. The guide pin 230 is also placed exterior tothe acetabulum 83.

With continued reference to FIGS. 13 and 14, the line 580 is definedthrough the interior spine 570, the guide bore 524, and the central post530 of the acetabular guide 500. According to various embodiments, theguide 520 and/or the guide bore 524 define a guide long axis 524 a. Thecentral post 530 defines a post long axis 530 a. The drill guide 122also defines the insert bore 126, and the drill guide 122 and/or theinsert bore 126 defines an insert long axis 126 a. The respective longaxes are of the various portions. The guide line 580 can be at leastpartially defined as a line through at least the post long axis 530 aand one of the guide long axis 524 a or the insert long axis 126 a. Theguide line 580 then extends to intersect the inferior ischial spine 570.

As discussed above, the shape and geometry of the acetabular guide 500can be formed such that the acetabular guide 500 engages the acetabulum82 in a manner such that the seating or engaging of the acetabular guide500 is achieved when the alignment bore 524 is aligned along the line580. Thus, the guide 500 is designed and manufactured to register withthe acetabulum 82 of the specific patient in a single location andorientation. The design of the guide 500 can be based on images of thepatient, as discussed above.

The single orientation and location of the guide 500 is generallyrelative to the inferior ischial spine 570. The guide line 580 isdesigned and selected to pass through the inferior ischial spine 570, asillustrated in FIG. 14. The one or more images acquired of the patientallows for determining of a geometry for designing and manufacturing theguide 500, such as the dome 504 and/or registration hooks 510, toproperly engage the acetabulum 82 of the patient such that the alignmentbore 524 is positioned on the line 580.

As discussed above, the insertion device 300 can be used to position theacetabular guide 500 within the acetabulum 82 to achieve the alignmentof the alignment bore 524 with the spine 570 along the line 580. Thedrill guide insert 122 can be positioned within the guide bore 524 in aselected manner, such as that discussed above. For example, the drillguide 122 can include an external taper then engages an internal taperof the alignment bore 524 to ensure a substantially aligned fit of thedrill guide 122. The alignment pin 230 can then be drilled into thepelvis of the patient to position the alignment pin 230 on the line 580.

Accordingly, the acetabular guide 500 can be used to align and guide thealignment pin 230 into the pelvis of the patient to allow for guiding oralignment of various instruments following positioning of the alignmentpin 230. For example, a reamer instrument, an insertion instrument foran acetabular shell, and/or other instrument can be provided to alignwith the alignment pin 230 once it is positioned within the pelvis. Asdiscussed above, the drill guide member 122 can be removed from thealignment bore 524 and moved along the length of the alignment pin 230to remove it from the patient. The acetabular guide 500 can then beremoved from the alignment pin 230, such as through a side opening 533formed through the alignment guide 520. Therefore, the acetabular guide500 need not be removed along the length of the alignment pin 230, butcan be removed with a sideways or lateral motion.

In positioning the alignment pin 230 on the line 580, the alignment pin230 can be positioned external to the acetabulum 82. Additionally, thepositioning of the alignment pin 230 on the line 580 external to theacetabulum 82 positions the alignment pin 230 in a region of the pelvis80 that is superior to the acetabulum 82 and posterior to the anteriorinferior spine. Generally, the region superior to the acetabulum canprovide substantially dense and strong bone of the pelvis for engagingthe alignment pin 230. Accordingly, the alignment pin 230 can be firmlyheld in the pelvis relative to the acetabulum 82 during a procedure. Thealignment pin 230 can be positioned within the pelvis of a patient forperforming a procedure on the acetabulum and is generally selected to bemaintained in a single orientation and location once placed.Accordingly, positioning the alignment pin 230 in substantially densebone can assist in maintaining the alignment pin 230 in the selectedlocation after the alignment pin 230 is positioned within the pelvis ofthe patient. Accordingly, the positioning the alignment bore 524 on theline 580 can assist in assuring that the alignment pin 230 will engage aselectively strong and dense bone portion to assure maintaining theselected position and orientation of the alignment pin 230 during therest of the procedure.

The procedure can then proceed, as discussed above, including reamingthe acetabulum 82 by aligning a reamer shaft with the alignment pin 230,placing an acetabular shell within the acetabulum 82 by aligning theinserter shaft with the alignment pin 230, and other procedure portionswhere the alignment pin 230 provides a reference for a user relative tothe pelvis for performing a procedure in the acetabulum. Again, theacetabular guide 500 can be initially positioned within the acetabulum82 in a substantially precise location and orientation based upon thegeometry of the acetabular guide 500, including the external dome 504.The geometry of the acetabular guide 500 can ensure that the acetabularguide 500 engages the patient in substantially single and pre-selectedorientation and location to ensure that the alignment bore 524 ispositioned relative to the patient in the pre-selected location andorientation. Therefore, the alignment pin 230 that is passed through thealignment bore 524 is at the selected location and orientation generallyon the line 580 and external to the acetabulum 82.

Various patient-specific guides, secondary guides, reamers, guidehandles, inserters, impactors, support devices, electronic positionersand other instruments can be used in various combinations and based onsurgeon preferences or patient and preoperative or intraoperativecircumstances for preparing an acetabulum and guiding and implanting anacetabular implant along a preoperatively determined alignmentorientation. In this respect, tools and instrumentation providingredundant functionality and of different embodiments may provide to thesurgeon in a kit or per surgeon's request.

For example, adaptors and other instruments described above can beprovided and used in various combinations within the scope of themethods described herein.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the present teachings without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

What is claimed is:
 1. An acetabular guide system, comprising: anacetabular guide, including: an exterior surface configured to have ageometry to substantially engage the acetabulum of a specific patient; acentral post extending from an interior surface of the acetabular guide;a second post extending from the interior surface of the acetabularguide substantially parallel to but offset relative to the central postalong a radial direction; and a guide inserter having an elongated shaftdefining an internal bore; wherein the internal bore of the elongatedshaft is configured to engage an exterior surface of the central post tomove the acetabular guide into the acetabulum.
 2. The acetabular guidesystem of claim 1, wherein the exterior surface is curved to contact theacetabulum of a specific patient.
 3. The acetabular guide system ofclaim 1, wherein the exterior surface is dome shaped.
 4. The acetabularguide system of claim 1, wherein the central post extends away from theinterior surface of the acetabular guide and is closed to an environmentoutside of the central post.
 5. The acetabular guide system of claim 1,wherein the guide inserter includes at least a first finger to engagethe second post when the central post is engaged within the internalbore of the guide inserter, wherein the guide inserter has rotationaland axial control of the acetabular guide to position the acetabularguide within the acetabulum.
 6. The acetabular guide system of claim 1,wherein the guide inserter includes an elongated portion with a handleand an inserter tip that is removable from the elongated portion.
 7. Theacetabular guide system of claim 1, wherein guide inserter tip includesa bore configured to engage the central post.
 8. The acetabular guidesystem of claim 1, wherein the guide inserter includes first and secondflanges that define an open channel that is configured to receive andhold the second post while the central post is received in the bore. 9.The acetabular guide system of claim 1, further comprising: a pin guidedefining a guide bore extending exterior to the interior surface; and aguide line formed between the central post with the inserter engagedthereto and the guide bore, wherein the guide line is configured to bealigned with an inferior ischial spine of the specific patient due tothe geometry of the exterior surface.
 10. The acetabular guide system ofclaim 8, wherein the guide line is configured to be aligned with aninferior ischial spine of the specific patient due to the geometry ofthe exterior surface.
 11. The acetabular guide system of claim 9,further comprising: a pin guide insert defining an insert bore, whereinthe pin guide insert is placed in the guide bore such that the insertbore is disposed on the guide line.
 12. The acetabular guide system ofclaim 11, wherein the guide pin configured to be passed through theinsert bore to engage a region of a pelvis superior to the acetabulum onthe guide line.
 13. An acetabular guide system, comprising: anacetabular guide, including: an exterior curved surface configured witha geometry to substantially match the acetabulum of a specific patientbased on a geometry of the acetabulum of the specific patient; a centralpost extending from an interior surface of the acetabular guide; asecond post extending from the interior surface of the acetabular guidesubstantially parallel to but offset relative to the central post alonga radial direction; and a guide inserter having an elongated shaftdefining an internal bore, wherein the guide inserter includes a firstfinger to engage the second post when the central post is engaged withinthe internal bore of the guide inserter; wherein the internal bore ofthe elongated shaft is configured to engage an exterior surface of thecentral post to move the acetabular guide into the acetabulum and theguide inserter has rotational and axial control of the acetabular guideto position the acetabular guide within the acetabulum.
 14. Theacetabular guide system of claim 13, wherein the guide inserter includesa guide inserter tip having a bore configured to engage the centralpost.
 15. The acetabular guide system of claim 13, wherein the firstfinger comprises first and second flanges that define an open channelthat is configured to receive and hold the second post while the centralpost is received in the bore.
 16. The acetabular guide system of claim13, further comprising: a pin guide defining a tapered guide bore havingan internal tapered surface extending from the exterior curved surface;a pin guide insert having an external tapered surface complementary withthe internal tapered surface and defining an insert bore; and a guideline that is defined by a first point on a first longitudinal axisthrough the central post and a second point on a second longitudinalaxis through the pin guide, wherein guide pin is configured to passthrough the insert bore and engage a region of a pelvis superior to theacetabulum on the guide line, and wherein positioning the acetabularguide within the acetabulum with the guide inserter aligns the insertbore along the guide line relative to an inferior ischial spine of thepatient.
 17. The acetabular guide system of claim 12, furthercomprising: at least one registration hook extending from an acetabulumguide rim and formed to connect with the pin guide, wherein theregistration hook is configured to contact near an acetabular rim whenthe exterior curved surface is engaged in the acetabulum.
 18. Anacetabular guide system, comprising: an acetabular guide, including: anexterior curved surface; a central post extending from an interiorsurface of the acetabular guide; a second post extending from theinterior surface of the acetabular guide substantially parallel to butoffset relative to the central post along a radial direction; a pinguide defining a bore extending from the exterior curved surface; aguide inserter having an elongated shaft defining an internal bore,wherein the guide inserter configured to engage at least one of thecentral post and the second post; a pin guide insert configured tocouple with the pin guide and defining an insert bore; a guide line thatis defined by a first point on a first longitudinal axis through thecentral post and a second point on a second longitudinal axis throughthe pin guide; wherein the internal bore of the elongated shaft isconfigured to engage an exterior surface of the central post to move theacetabular guide into the acetabulum and the guide inserter hasrotational and axial control of the acetabular guide to position theacetabular guide within the acetabulum and align the insert bore alongthe guide line relative to an inferior ischial spine of the patient. 19.The acetabular guide system of claim 18, wherein the guide inserterincludes a first finger to engage the second post when the central postis engaged within the internal bore of the guide inserter.
 20. Theacetabular guide system of claim 19, wherein the first finger comprisesfirst and second flanges that define an open channel that is configuredto receive and hold the second post while the central post is receivedin the bore.